Surf ropes are dirt cheap and not worth the hassle of trying to make yourself. I got a 20' rope from my Tige dealer for free when I bought my board. I think it retailed for $40, which is worth it to not have to waste time trying to figure out the right lengths and trying to add padding if desired.

He wants to make one that, that is his prerogative. I cant help you with the braid, but I would suggest you use a rope with a braided sheath (kernmantle) and use a thicker rope as well. Thin rope is dangerous. I made one for about $24 and it actually fits my requirements quite well. FYI, not all surf ropes are long enough for some boats and towers, especially the larger boats. I used a piece of Schedule 40, 3/4" CPVC pipe about 9-10" long as the handle and use a double figure of 8 knot to secure it back to the main strand (triangle). You tie one figure of 8 then slide on the plastic pipe and retrace the figure of 8 to secure it. Then, about every 2' to the sweet spot I tied a simple knot. I put on a couple of pieces of pool noodle to act as floats near the handle. Due to the rope thickness, I tied a smaller section to the end with a sheet bend knot for the tower hook. Initially i just had one big knot at the end, but the handle is so much easier to use!